Instant food

ABSTRACT

Legume-derived, and particularly soybean-derived, water-soluble polysaccharides are added to thickener-containing powder supplied with an instant food to prevent clumping of powder masses during reconstitution and for a more homogeneous reconstitution. Thus, the problem is solved which is encountered with soup powders such as a thickened soup powder and a curry-seasoned soup powder, which are supplied with instant foods such as instant noodles, containing thickeners such as starch or gum substances to impart thickness, whereby reconstitution in a stationary state produces swelling of the thickener and prevents adequate dispersion, resulting in scattering of powder masses in the soup and clumping at the bottom of the container and, thereby, impairing the taste.

FIELD OF THE INVENTION

The present invention relates to an instant food comprising athickener-containing powder.

BACKGROUND ART

Instant foods such as instant noodles are packaged with powderedseasonings for preparation of starch sauce soups or curry soups. In thecase of powdered instant soups, cup soups and the like, such productscan be fully prepared by adding hot water either after transferring thepowder to a separate cup or using the cup provided with the product, orelse adding water and heating the mixture in a microwave oven.

In most cases, the powders contain various thickening agents such asstarches or gums for the purpose of imparting a heat-insulating effector thickness. Such instant foods are usually packaged in a containerserving as both the reconstituting vessel and the serving bowl; however,often the food is not suited for stirring after addition of the hotwater, or it may be necessary to allow the food to stand for severalminutes without stirring after microwave heating, such that in manycases the food remains reconstituted, and in a stationary state, untilconsumption. When the instant food is prepared in a stationary state,the thickener in the seasoning tends to swell and this results ininsufficient dispersion, producing powder masses which become scatteredin the soup or clump at the bottom of the container, thereby impairingthe taste.

Japanese Unexamined Patent Publication No. 11-290000 discloses a methodof dispersing a starch-containing powdered food, but the effect thereofis inadequate and the method has not satisfactorily solved the problemsencountered with stationary reconstitution of most instant noodles orcup soups.

Also, Japanese Unexamined Patent Publication No. 9-289880 discloses amethod of reacting soybean polysaccharides with starch foods to reducethe viscosity of the gelatinized starch of starch-containing foods, toprevent the gelling which occurs after cooling, but this disclosure onlydescribes the various effects of heating and cooling on starch solutionsand does not deal with solving the aforementioned problem encounteredwith instant foods.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to prevent the clumping of aninstant food, packaged with a thickener-containing powder, which occurswhen it is reconstituted, in order to achieve uniform reconstitution ofthe powder.

As a result of much diligent research on the problem described above,the present inventors completed this invention after discovering that itis effective to add legume-derived, and particularly soybean-derived,water-soluble polysaccharides to powders supplied with instant foods.

Specifically, the present invention provides an instant food comprisinga powder which contains a mixture of both a thickener and legume-derivedwater-soluble polysaccharides. The thickener may be starch, and thewater-soluble polysaccharides used are preferably ones derived fromsoybean. The instant food is particularly useful when applied for a foodpackaged with a container serving as both the reconstitution vessel andthe serving bowl.

BEST MODE FOR CARRYING OUT THE INVENTION

The thickener used may be a food containing wheat flour, rice flour, orpotato, azuki bean, pea or arrowroot starch, or various modified formsof wheat starch or potato starch, or a gum substance such as dextrin,guar gum or xanthan gum. The amount will differ depending on the type ofinstant food, the container volume, and the types and amounts ofseasonings.

The water-soluble polysaccharides used for the invention is derived fromlegumes, and various legumes including soybean, azuki bean, green peas,horse bean, kidney bean and the like may be used as polysaccharidesources according to the invention, although using soybean as the sourceis particularly advantageous because soybean is produced in largeamounts and is readily available in the form of okara. The soybean ismost preferably cotyledonous.

The water-soluble polysaccharides may be of any molecular weight, but itpreferably has an average molecular weight of from a several thousand toa several million, and most preferably between 5000 and 1 million. Ifthe molecular weight is too high the viscosity will be excessivelyincreased, and the water-soluble polysaccharides will be responsible foran increased viscosity of the soup when boiling water is poured into theinstant food or the food is heated in a microwave oven, thereby makingit impossible to achieve an adequate effect. Throughout the presentspecification, the average molecular weight of the water-solublepolysaccharides is the value determined by the limiting viscosity methodwherein the viscosity is measured in a 0.1 M NaNO₃ solution usingstandard pullulan (product of Showa Denko K.K.) as the standardsubstance, while the uronic acid is measured by the Blumenkrantz method.

The water-soluble polysaccharides may be obtained by water extractionfrom a polysaccharide-containing raw material or, if necessary, byheated elution under acidic or alkaline conditions, or it may be elutedby decomposition with an enzyme. The method applied to production of thelegume-derived water-soluble polysaccharides may be any publicly knownmethod, an example of which is described below.

In the case of soybean, for example, the okara by-product fromproduction of tofu, soy milk or separated soybean protein may beutilized.

The raw material may be subjected to hot extraction under acidic oralkaline conditions, preferably at a pH near the isoelectric point ofeach protein, and preferably at 80° C. or higher and more preferablyfrom 100-130° C. to separate out the water-soluble fraction, and theneither dried directly or dried after removal of the hydrophobicsubstances or low molecular weight substances by, for example, activatedcarbon treatment, resin adsorption treatment or ethanol precipitationtreatment, to obtain water-soluble hemicellulose. The water-solublepolysaccharide extracted in this manner preferably comprises uronic acidat 5-50% and, more preferably, at 5-40%.

The amount of water-soluble polysaccharides used is not particularlyrestricted, and may be 0.01-10.0%, preferably 0.05-5.0% and morepreferably 0.1-2.0% with respect to the thickener included in the powderof the instant food. If the content is too high, an effect of anincreased viscosity of the prepared powder-reconstituted solution willnot be adequate, while if it is too low, it will be difficult to achievean effect of uniform reconstitution in a stationary state.

The powder of the instant food may additionally contain various publiclyknown powder emulsifiers, inorganic substances such as silicon oxide, orstabilizers and the like which are commonly used in instant foods, andit may also contain various powdered extracts, spices, flavorings, fatsand oils, gustatory additives, seasonings, coloring agents and the like.

The instant food itself will typically be dry noodles or instant soup,but may be any type of dry food including various types of agriculturalproducts, livestock products or marine products, either in powdered orgranular form. Such instant foods may be packaged in a container servingas both the reconstituting vessel and the serving bowl, and the powderedportion may be sealed in a plastic bag if desired.

EXAMPLES

Preferred embodiment of the invention will now be explained throughexamples, with the understanding that the invention is not limited tothese examples. Unless otherwise specified, the parts and percentagevalues in the examples are based on weight.

Example 1 Preparation of Water-Soluble Polysaccharides

Distilled water was added in a 3-fold amount to okara (20% solidportion) obtained as a by-product during the production of isolatedsoybean protein using defatted soybean and, after adjusting the pH to4.5 with hydrochloric acid, the mixture was heated at 120° C. for 90minutes for extraction of the water-soluble polysaccharides. Theextraction was followed by centrifugation (1000 G×20 min) for separationof the supernatant containing the water-soluble polysaccharides. Theseparated supernatant was subjected to granular activated carbon columntreatment, and after purification was spray dried. Analysis of thewater-soluble polysaccharides obtained in this manner yielded aviscosity-average molecular weight of about 150,000 and a uronic acidcontent of 18%.

Example 2

A commercially available instant noodle product packaged with sauce andcontainer was purchased, and the two different powdered curry seasoningslisted in the following table were prepared for use in place of thesauce, to produce instant foods having the powdered seasonings laid overinstant cup noodles at a rate of 13 g with respect to 100 g of theinstant noodles. (The soybean water-soluble polysaccharides shown in thetable was the same as in Example 1.) When 300 g of hot water was pouredover the food and the mixture was allowed to stand for 3 minutes, andthe state of the soup was examined, an obvious difference was noticed interms of generation of masses and uniformity of thickness. TABLE 1Ingredients (pts. by wt.) Example 2 Comp. Ex. 1 Potato starch 20.0  20.0Salt 17.0  17.0 Curry powder 5.0  5.0 Beef extract powder 12.0  12.0Powdered vegetable 4.0  4.0 Food coloring 0.4  0.4 Water-soluble soybean0.2 — polysaccharides State after reconstitution Powder masses Virtuallynone Notable Viscosity Uniform thickness Non-uniform thickness

Example 3

An instant food was prepared by placing 3 g of freeze-dried corn grainsand 20 g of the powdered corn potage soup shown in Table 2 into a 250 mlcontainer. After pouring 150 g of hot water over the food and stirring 5times with a spoon, the mixture was allowed to stand for 2 minutes, andthe state was observed. The generation of masses and uniformity ofthickness of this food product was clearly superior to that of thecomparison food product. TABLE 2 Ingredients (pts. by wt.) Example 2Comp. Ex. 1 Corn powder 10.0  10.0  Potato starch 21.0  21.0  Skim milkpowder 5.0 5.0 Lactose 25.0  25.0  Salt 4.0 4.0 Dextrin 9.0 9.0Monosodium glutamate 2.5 2.5 Powdered food oil 2.0 2.0 Spice dash dashColoring agent dash dash Edible vegetable oil 10.0  10.0  Water-solublesoybean 0.2 polysaccharides State after preparation Powder massesVirtually none Notable Viscosity Uniform thickness Non-uniform thickness

INDUSTRIAL APPLICABILITY

The results described above demonstrate that thickener-containing powderwith an added water-soluble polysaccharides can contribute topreparation of an instant food with satisfactory reconstitutability evenwith stationary preparation and minimal stirring.

1. An instant food comprising a powder which contains a mixture of botha thickener and legume-derived water-soluble polysaccharides, theinstant food being reconstitutable by addition of hot water to theinstant food.
 2. (canceled)
 3. An instant food according to claim 1,wherein the legume is soybean.
 4. An instant food according to claim 1,wherein the instant food is packaged with a container which serves asboth a reconstituting vessel and a serving bowl.